The perimeter of a square is $4$ units. How long is each side?
$\text{? }$ The perimeter is the total length of all the sides of the shape added together. $ {\text{?}} + {\text{?}} + {\text{?}} + {\text{?}} = 4\text{ } $ $ {1} + {1} + {1} + {1} = 4\text{ } $ The sides of a square are all the same length, so each side must be $1$ unit long.